Grand Gulf nuclear power station is a General Electric boiling water reactor. It lies on a 2,100-acre (8.5 km²) site near Port Gibson, Mississippi. The site is wooded and contains two lakes. The plant has a 520-foot (158 m) cooling tower.

Grand Gulf is operated by Entergy Nuclear and owned jointly by System Energy Resources, Inc. (90%) and by South Mississippi Electric Power Association (10%).

Unit 3

On September 22, 2005 it was announced that Grand Gulf had been selected as the site for a GE ESBWR reactor. For details, see Nuclear Power 2010 Program. Next to the vacant, waiting Grand Gulf field is an unfinished concrete structure that was to be the containment structure for a twin to the existing unit. In December 1979, staggered by construction cost Entergy (then called Middle South Utilities) stopped work on this unit.

In 2007, the U.S. Nuclear Regulatory Commission (NRC) issued an Early Site Permit (ESP) to Grand Gulf. In 2008, Entergy and NuStart submitted a Combined Construction and Operating License (COL) application for a potential new nuclear unit at the Grand Gulf.

Surrounding population

The Nuclear Regulatory Commission defines two emergency planning zones around nuclear power plants: a plume exposure pathway zone with a radius of 10 miles (16 km), concerned primarily with exposure to, and inhalation of, airborne radioactive contamination, and an ingestion pathway zone of about 50 miles (80 km), concerned primarily with ingestion of food and liquid contaminated by radioactivity.

The 2010 U.S. population within 10 miles (16 km) of Grand Gulf was 6,572, a decrease of 18.6 percent in a decade, according to an analysis of U.S. Census data for msnbc.com. The 2010 U.S. population within 50 miles (80 km) was 321,400, a decrease of 0.4 percent since 2000. Cities within 50 miles include Port Gibson (5 miles to city center), Vicksburg (25 miles).

Seismic risk

The Nuclear Regulatory Commission's estimate of the risk each year of an earthquake intense enough to cause core damage to the reactor at Grand Gulf was 1 in 83,333, according to an NRC study published in August 2010.

Release of low levels of tritium into Mississippi River

After heavy rains in late April, 2011, workers were pumping standing water that had collected in the abandoned, never-completed Unit 2 turbine building into the Mississippi River. Detectors sounded alarms at the presence of tritium in the water, and the pumping was stopped, and the accidental release was reported to the Mississippi Health Department and to the NRC. As of the dates of the news reports, it was unknown both how much tritium had entered the river, and how the tritium had collected in the standing water, given that Unit 2 was not an operational reactor, had never been completed. It is unknown how much tritium entered the river, because samples were not taken at the time of the leak. The NRC is investigating to find the source of the leak.

Reactor data

The Grand Gulf Nuclear Generating Station consist of one operational reactor, two additional unit was cancelled.